It's hard to call Pownce anything other than a Twitter clone, so we won't hide it. Pownce is a Twitter clone. It doesn't work with Twitter, it's simply made its own service. But like the constant struggle between social networking sites, Pownce gives you two options: drag your friends into the mix or play by yourself.
The interface for Pownce seems a little dumbed down. Unlike Twitter where you can see the general Tweets that the world is posting, it doesn't seem like ?the public? is sending or receiving any of your messages. That means that unless your friends are willing to join up, the Pownce app for the iPhone is pretty useless.
You can send messages, pictures, links, and even post events, but who is really reading all of this? If you do have your friends on there, you can select exactly who you want to send the message to if it's not for everyones eyes. The frustrating part about Pownce is that when the app loads up for the first time, it requires you to open up Safari and confirm that it's ok for Pownce to grant this app permission. It's kind enough to load it back up for you after, but that just doesn't cut it.
Pownce does look very attractive and there aren't any issues with how it handles. The issue lies in the service. As it is, Twitter is very much a clique based service, so trying to muscle their way into that without offering something additional or even superior is kind of depressing. The app doesn't cost anything but your time, although it may take a lot of it to convince your entire contact list to give this app a whirl.